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<h1>AviSynth FAQ - General information</h1>

<h2>Contents</h2>
<ol>
  <li><a href="#What_is_AviSynth.3F">What is AviSynth?</a></li>
  <li><a href="#Who_is_developing_AviSynth.3F">Who is developing AviSynth?</a></li>
  <li><a href="#Where_can_I_download_the_latest_versions_of_AviSynth.3F">Where can I download the latest versions of AviSynth?</a></li>
  <li><a href="#What_are_the_main_bugs_in_these_versions.3F">What are the main bugs in these versions?</a></li>
  <li><a href="#Where_can_I_find_documentation_about_AviSynth.3F">Where can I find documentation about AviSynth?</a></li>
  <li><a href="#How_do_I_install/uninstall_AviSynth.3F">How do I install/uninstall AviSynth?</a></li>
  <li><a href="#What_is_the_main_difference_between_v1.0x,_v2.0x,_v2.5x,_v2.6x_and_v3.x.3F">What is the main difference between v1.0x, v2.0x,
v2.5x, v2.6x and v3.x?</a></li>
  <li><a href="#How_do_I_know_which_version_number_of_AviSynth_I_have.3F">How do I know which version number of AviSynth I
have?</a></li>
  <li><a href="#How_do_I_make_an_AVS-file.3F">How do I make an AVS-file?</a></li>
  <li><a href="#Where_do_I_save_my_AVS-file.3F">Where do I save my AVS-file?</a></li>
  <li><a href="#Are_plugins_compiled_for_v2.5x/v2.6x_compatible_with_v1.0x/v2.0x_and_vice_versa.3F">Are plugins compiled for v2.5x/v2.6x compatible with v1.0x/v2.0x and vice versa?</a></li>
  <li><a href="#How_do_I_use_a_plugin_compiled_for_v2.0x_in_v2.5x.3F">How do I use a plugin compiled for v2.0x in v2.5x?</a></li>
  <li><a href="#How_do_I_switch_between_different_AviSynth_versions_without_re-install.3F">How do I switch between different AviSynth
versions without re-install?</a></li>
  <li><a href="#VirtualdubMod.2C_WMP6.4.2C_CCE_and_other_programs_crash_every_time_on_exit_.28when_previewing_an_avs_file.29.3F">VirtualdubMod, WMP6.4, CCE and other programs
crash every time on exit (when previewing an avs file)?</a></li>
  <li><a href="#My_computer_seems_to_crash_at_random_during_a_second_pass_in_any_encoder.3F">My computer seems to crash at random during a second pass in any encoder?</a></li>
  <li><a href="#Is_there_a_command_line_utility_for_encoding_to_DivX.2FXviD_using_AviSynth.3F">Is there a command line utility for encoding to
DivX/XviD using AviSynth?</a></li>
  <li><a href="#Does_AviSynth_have_a_GUI_.28graphical_user_interface.29.3F">Does AviSynth have a GUI (graphical user
interface)?</a></li>
</ol>

<a name="What_is_AviSynth.3F"></a>
<h3>What is AviSynth?</h3>

<p>AviSynth (AVI SYNTHesizer) is a frameserver. An excellent description is
given on <a href="http://neuron2.net/LVG/avisynth.html" class="external text" title="http://neuron2.net/LVG/avisynth.html" rel="nofollow">Lukes
homepage</a>:</p>
<p>&quot;AviSynth is a very useful utility created by Ben Rudiak-Gould. It
provides many options for joining and filtering videos. What makes AviSynth
unique is the fact that it is not a stand-alone program that produces output
files. Instead, AviSynth acts as the &quot;middle man&quot; between your videos
and video applications.</p>
<p>Basically, AviSynth works like this: First, you create a simple text document
with special commands, called a script. These commands make references to one or
more videos and the filters you wish to run on them. Then, you run a video
application, such as Virtualdub, and open the script file. This is when AviSynth
takes action. It opens the videos you referenced in the script, runs the
specified filters, and feeds the output to video application. The application,
however, is not aware that AviSynth is working in the background. Instead, the
application thinks that it is directly opening a filtered AVI file that resides
on your hard drive.</p>
<p>There are five main reasons why you would want to use AviSynth:</p>
<ol>
  <li>Join Videos: AviSynth lets you join together any number of videos,
    including segmented AVIs. You can even selectively join certain portions of
    a video or dub soundtracks.</li>
  <li>Filter Videos: Many video processing filters are built in to AviSynth. For
    example, filters for resizing, cropping, and sharpening your videos.</li>
  <li>Break the 2 GB Barrier: AviSynth feeds a video to a program rather than
    letting the program directly open the video itself. Because of this, you can
    usually use AviSynth to open files larger than 2 GB in programs that don't
    natively support files of that size.</li>
  <li>Open Unsupported Formats: AviSynth can open almost any type of video,
    including MPEGs and certain Quicktime MOVs. However, when AviSynth feeds
    video to a program, it looks just like a standard AVI to that program. This
    allows you to open certain video formats in programs that normally wouldn't
    support them.</li>
  <li>Save Disk Space: AviSynth generates the video that it feeds to a program
    on the fly. Therefore, no temporary or intermediate videos are created.
    Because of this, you save disk space.&quot;</li>
</ol>

<a name="Who_is_developing_AviSynth.3F"></a>
<h3>Who is developing AviSynth?</h3>
<p>Originally AviSynth (up to v1.0b) was developed by Ben Rudiak-Gould. See <a href="http://neuron2.net/www.math.berkeley.edu/benrg/index.html" class="external text" title="http://neuron2.net/www.math.berkeley.edu/benrg/index.html" rel="nofollow">mirror
of his homepage</a>. Currently it is developed by Sh0dan, IanB, d'Oursse
(AviSynth v3), Bidoche (AviSynth v3) and <a href="http://sourceforge.net/project/memberlist.php?group_id=57023">others</a>.</p>

<a name="Where_can_I_download_the_latest_versions_of_AviSynth.3F"></a>
<h3>Where can I download the latest versions of AviSynth?</h3>
<p>The most recent stable version is v2.57, which can be found <a href="http://sourceforge.net/project/showfiles.php?group_id=57023" class="external text" title="http://sourceforge.net/project/showfiles.php?group_id=57023" rel="nofollow">here</a>
(just as more recent builds).</p>

<a name="What_are_the_main_bugs_in_these_versions.3F"></a>
<h3>What are the main bugs in these versions?</h3>
<p>Current bugs can be found in the documentation on the <a href="http://sourceforge.net/tracker/?atid=482673&amp;group_id=57023" class="external text" title="http://sourceforge.net/tracker/?atid=482673&amp;group_id=57023" rel="nofollow">AviSynth
project page</a>. Fixed bugs can be found in the <a href="changelist.htm" title="Changelist">Changelist</a>.</p>

<a name="Where_can_I_find_documentation_about_AviSynth.3F"></a>
<h3>Where can I find documentation about AviSynth?</h3>
<p>Documentation about the filters of AviSynth can be found on this site <a href="http://avisynth.org/mediawiki/Main_Page" title="Main Page">Main
Page</a>, and in particular here: <a href="corefilters.htm" title="Internal filters">Internal
filters</a>. You should read these documents before posting to the forum, but
it's OK to post if you have trouble understanding them.</p>

<a name="How_do_I_install/uninstall_AviSynth.3F"></a>
<h3>How do I install/uninstall AviSynth?</h3>
<p>Starting from v2.06 AviSynth comes with an auto installer. Also make sure you
have no other versions of AviSynth floating around on your harddisk, because
there is a chance that one of those versions will be registered. Remove them if
necessary. For uninstalling AviSynth go to &quot;program&quot;, &quot;AviSynth
2.5&quot; and select &quot;Uninstall AviSynth&quot;.</p>
<p>Installing AviSynth v2.05 or older versions: move avisynth.dll to your
system/system32 directory and run install.reg. For uninstalling run
uninstall.reg and delete avisynth.dll.</p>

<a name="What_is_the_main_difference_between_v1.0x,_v2.0x,_v2.5x,_v2.6x_and_v3.x.3F"></a>
<h3>What is the main difference between v1.0x, v2.0x,
v2.5x, v2.6x and v3.x?</h3>
<p>The versions v1.0x and v2.0x are compatible and outdated. The main difference
with v2.5x is that the internal structure of AviSynth has changed (YV12 and
multichannel support) with the consequence that external plugins compiled for
v1.0x/v2.0x will not work for v2.5x/v2.6x and vice versa. In v2.6x other planar
formats like YV24 and Y8 are added. v2.5x plugins will work in v2.6x but not
vice-versa. All versions are incompatible with v3.x, which will also work under
Linux/MacOSX (see <a href="http://avisynth.org/mediawiki/AviSynth_v3" title="AviSynth v3">AviSynth
v3</a>) and rely on the GStreamer API.</p>

<a name="How_do_I_know_which_version_number_of_AviSynth_I_have.3F"></a>
<h3>How do I know which version number of AviSynth I have?</h3>
<p>Open a text-editor, for example notepad. Add the following line</p>
<pre>Version()</pre>
<p>and save the file with the extension &quot;avs&quot;. Save for example as
&quot;version.avs&quot; (make sure that the extension is &quot;avs&quot; and not
&quot;txt&quot;). Open the file in an application which can read AVI-files, for
example WMP 6.4 or Media Player Classic. The version number will be displayed.</p>

<a name="How_do_I_make_an_AVS-file.3F"></a>
<h3>How do I make an AVS-file?</h3>
<p>Use your preferred text editor (e.g. Notepad). See also <a title href="#How_do_I_know_which_version_number_of_AviSynth_I_have.3F">this</a>.</p>
<p>Although AviSynth doesn't need them, there are several GUIs (graphical user
interface) which may help you writing your AVS files. You can read a description
for each one of them <a href="#Does_AviSynth_have_a_GUI_.28graphical_user_interface.29.3F" title>here</a>.</p>
<h3>Where do I save my AVS-file?</h3>
<p>Anywhere on your hard-disk.</p>

<a name="Are_plugins_compiled_for_v2.5x/v2.6x_compatible_with_v1.0x/v2.0x_and_vice_versa.3F"></a>
<h3>Are plugins compiled for v2.5x/v2.6x compatible
with v1.0x/v2.0x and vice versa?</h3>
<p>As explained <a href="#What_is_the_main_difference_between_v1.0x,_v2.0x,_v2.5x,_v2.6x_and_v3.x.3F">here</a> that is not the case. However
it is possible to use a v1.0x/v2.0x plugin in v2.5x/v2.6x, as explained <a title href="#How_do_I_use_a_plugin_compiled_for_v2.0x_in_v2.5x.3F">here</a>.</p>

<a name="How_do_I_use_a_plugin_compiled_for_v2.0x_in_v2.5x.3F"></a>
<h3>How do I use a plugin compiled for v2.0x in v2.5x?</h3>

<p>In plugin collection <a href="externalfilters/warpsharp.htm">warpsharp_2003_1103.cab</a>
you
will find a plugin called &quot;LoadPluginEx.dll&quot;. (When using an older
version of LoadPluginEx.dll, don't move this plugin to your plugin dir. But move
it to a separate folder, otherwise VirtualdubMod and WMP6.4 will crash on exit.)
This will enable you using v2.0x plugins in v2.5x. An example script (using the
v2.0x plugin Dust by Steady):</p>
<pre>LoadPlugin(&quot;C:\Program Files\avisynth2_temp\plugins\LoadPluginEx.dll&quot;)
LoadPlugin(&quot;C:\Program Files\avisynth2_temp\plugins\dustv5.dll&quot;)

AviSource(&quot;D:\clip.avi&quot;)
ConvertToYUY2()
PixieDust(5)</pre>
<p>If you want to automate this process, have a look at <a href="http://avisynth.org/mediawiki/LoadOldPlugins" title="LoadOldPlugins">LoadOldPlugins</a>.</p>

<a name="How_do_I_switch_between_different_AviSynth_versions_without_re-install.3F"></a>
<h3>How do I switch between different AviSynth
versions without re-install?</h3>
<ul>
  <li>You can use AvisynthSwitcher available <a href="http://www.lalternative.org" class="external text" title="http://www.lalternative.org" rel="nofollow">here</a>.
    Versions v2.08 and v2.50 are provided, but you can easily add a new one
    under AvisynthSwitcher\versions\Avisynth 2.x.x.</li>
</ul>
<ul>
  <li>Some other ways are described <a href="http://forum.doom9.org/showthread.php?s=&amp;threadid=45181" class="external text" title="http://forum.doom9.org/showthread.php?s=&amp;threadid=45181" rel="nofollow">here</a>.</li>
</ul>

<a name="VirtualdubMod.2C_WMP6.4.2C_CCE_and_other_programs_crash_every_time_on_exit_.28when_previewing_an_avs_file.29.3F"></a>
<h3>VirtualdubMod, WMP6.4, CCE and other programs
crash every time on exit (when previewing an avs file)?</h3>
<p>This problem can be caused by certain plugins in your (autoloading) plugin
folder. The solution is to move the problematic plugins outside your plugin
folder and load them manually.&nbsp;</p>

<a name="My_computer_seems_to_crash_at_random_during_a_second_pass_in_any_encoder.3F"></a>
<h3>My computer seems to crash at random during a
second pass in any encoder?</h3>
<p>AviSynth is highly optimized. As a consequence it is possible that your
computer seems to crash at random during a second pass. Try running the <a href="http://www.mersenne.org/freesoft.htm" class="external text" title="http://www.mersenne.org/freesoft.htm" rel="nofollow">Prime95</a>
stress test for an hour, to check if your system is stable. If this test fails
(or your computer locks up) make sure that your computer is not overclocked and
lower your bus speed of your processor in steps of (say) five MHz till the
crashes are gone.</p>

<a name="Is_there_a_command_line_utility_for_encoding_to_DivX.2FXviD_using_AviSynth.3F"></a>
<h3>Is there a command line utility for encoding to
DivX/XviD using AviSynth?</h3>

<ul>
  <li>There is a command line utility called <a href="http://www.avs2avi.org/" class="external text" title="http://www.avs2avi.org/" rel="nofollow">AVS2AVI</a>
    (and AVS2AVI GUI) for encoding to DivX / XviD using AviSynth. [<a href="http://forum.doom9.org/showthread.php?t=71493" class="external text" title="http://forum.doom9.org/showthread.php?t=71493" rel="nofollow">discussion</a>]</li>
  <li><a href="http://forum.doom9.org/showthread.php?t=98469" class="external text" title="http://forum.doom9.org/showthread.php?t=98469" rel="nofollow">xvid_encraw</a>
    for encoding to XviD in M4V. Use <a href="http://kurtnoise.free.fr/index.php?dir=mp4tools/" class="external text" title="http://kurtnoise.free.fr/index.php?dir=mp4tools/" rel="nofollow">mp4box</a>
    or <a href="http://forum.doom9.org/showthread.php?t=115459" class="external text" title="http://forum.doom9.org/showthread.php?t=115459" rel="nofollow">YAMB</a>
    to mux it into MP4.</li>
</ul>

<a name="Does_AviSynth_have_a_GUI_.28graphical_user_interface.29.3F"></a>
<h3>Does AviSynth have a GUI (graphical user
interface)?</h3>
<p>AviSynth doesn't have a full fledged gui, but several tools are available:</p>
<ul>
  <li><a href="http://avisynth.org/mediawiki/VirtualDubMod" title="VirtualDubMod">VirtualDubMod</a>:
    The following AviSynth related utilities are present:
    <ul>
      <li>'Open via AVISynth' command: This allows you to open any AviSynth
        compatible video file by automatically generating a suitable script by a
        selectable template.</li>
      <li>AVS Editor (Hotkey Ctrl+E): Just open your AVS and under tools select
        &quot;script editor&quot;. Change something and press F5 to preview the
        video.</li>
    </ul>
  </li>
  <li>AvisynthEditor: This is an advanced AviSynth script editor featuring syntax
    highlighting, auto-complete code and per version plugin definition files. <a href="http://www.lalternative.org/img/AvisynthEditor.gif" class="external text" title="http://www.lalternative.org/img/AvisynthEditor.gif" rel="nofollow">Here
    is a screenshot</a>. It can be found <a href="http://www.lalternative.org" class="external text" title="http://www.lalternative.org" rel="nofollow">here</a>.
    Discussion can be found on <a href="http://forum.doom9.org/showthread.php?s=&amp;threadid=49487" class="external text" title="http://forum.doom9.org/showthread.php?s=&amp;threadid=49487" rel="nofollow">Doom9.org
    forum</a>.</li>
  <li><a href="http://www.yeomanfamily.demon.co.uk/avsgenie/avsgenie.htm" class="external text" title="http://www.yeomanfamily.demon.co.uk/avsgenie/avsgenie.htm" rel="nofollow">AVSGenie</a>:
    AVSGenie allows the user to select a filter from a drop down list or from a
    popup menu. An editable page of parameters will then be brought into view,
    with a guide to the filter and it's parameters. A video preview window
    opens, showing &quot;source&quot; and &quot;target&quot; views. The source
    window, in simple cases, shows output of the first line of the script,
    generally an opened video file. The target window shows the output of the
    whole script. In this way, effects of filters can easily be seen. The line
    which represents the source window can be changed. Discussion can be found <a href="http://forum.doom9.org/showthread.php?s=&amp;threadid=54090" class="external text" title="http://forum.doom9.org/showthread.php?s=&amp;threadid=54090" rel="nofollow">here</a>.</li>
  <li><a class="external text" title="http://www.swiftavs.net" rel="nofollow" href="http://sourceforge.net/project/showfiles.php?group_id=74272">SwiftAVS
    (by Snollygoster)</a>: Another nice gui, formerly known as AviSynthesizer. [<a href="http://forum.doom9.org/showthread.php?s=&amp;threadid=48326" class="external text" title="http://forum.doom9.org/showthread.php?s=&amp;threadid=48326" rel="nofollow">discussion</a>]</li>
  <li><a href="http://avisynth.org/qwerpoi/Download.html">AvsP</a>: It's a
    tabbed script editor for Avisynth. It has many features common to
    programming editors, such as syntax highlighting, autocompletion, call tips.
    It also has an integrated video preview, which when coupled with tabs for
    each script make video comparisons a snap. What really makes AvsP unique is
    the ability to create graphical sliders and other elements for any filter's
    arguments, essentially giving Avisynth a gui without losing any of its
    powerful features. Discussion can be found <a href="http://forum.doom9.org/showthread.php?t=129385">here</a>.</li>
</ul>
<p>|<a href="faq_sections.htm" title="AviSynth FAQ"> Main Page</a> | <b>General
Info</b> | <a href="faq_loading_clips.htm" title="FAQ loading clips">Loading Clips</a>
| <a href="faq_frameserving.htm" title="FAQ frameserving">Loading Scripts</a> | <a href="faq_common_errors.htm" title="FAQ common errors">Common
Error Messages</a> | <a href="faq_different_types_content.htm" title="FAQ different types content">Processing
Different Content</a> | <a href="faq_yv12.htm" title="FAQ YV12">Dealing with
YV12</a> | <a href="faq_using_virtualdub_plugins.htm" title="FAQ using virtualdub plugins">Processing
with Virtualdub Plugins</a> |</p>
<p>
<kbd>$Date: 2008/10/26 14:18:53 $</kbd>
</p>
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